Means for controlling the drying of textiles and reclaiming the liquid therefrom

ABSTRACT

A means for controlling the drying of textiles which contains a cleaning solvent or a mixture of cleaning solvent and water, the textiles being placed in a rotatable tumbling drum, then subjected to air maintained below atmospheric pressure, the air passing through the drum and subsequently through cooling units which condense the vapor removed by the air. Means are provided for varying the drying procedure such as heating the air; recirculating and reheating a preselected portion of the air; recirculating selected portions of the air without heating; introducing ambient air; and controlling the total volume of the air.

United States Patent 1191 Freze 1 Aug. 27, 1974 [54] MEANS FORCONTROLLING THE DRYING 2,064,084 12/1936 Sando 34/131 0F TEXTILES ANDRECLAINHNG THE 2,166,294 7/1939 Hetzer 34/131 2910,783 ll/l959 Hoyt34/77 LIQUID THEREFROM 3,408.083 10/1968 Symanski 34/242 [75] lnventor:Benjamin H. Freze, Garden Grove,

Calif- Primary Examiner-Kenneth W. Sprague Assistant Examiner-James C.Yeung h k [73] Asslgnee g fllg gg Bros Incorporated Attorney, Agent, orFzrmLyon & Lyon PP N04 287,688 A means for controlling the drying oftextiles which contains a cleaning solvent or a mixture of cleaning 52us. 01 34/131, 34/77 34/133 when and Water, the textiles being Placed ina rotat- [18 able tumbling drum, then subjected to air maintained 511111.01. F26b 11/02 below atmospheric Pressure, the air Passing through[58] Field of Search 34/72 73-77 the drum and Subsequently hmugh coolingnits I'4 242 140, which condense the vapor removed by the air. Means68/18 C 18 are provided for varying the drying procedure such as heatingthe air; recirculating and reheating a prese- [56] References Citedlected portion of the air; recirculating selected portions of the airwithout heating; introducing ambient UNITED STATES PATENTS air; andcontrolling the total volume of the air. 1,564,566 12/1925 Harris 34/2251.947.174 2/1934 Sando 34 77 5 Claims, 7 Drawing Flgures MEANS FORCONTROLLING THE DRYING OF TEXTILES AND RECLAIMING THE LIQUID THEREFROMBACKGROUND OF THE INVENTION The drying of textiles containing a cleaningsolvent, or a mixture of a cleaning solvent and water, has beenaccomplished in essentially the same manner as the drying of watersoaked textiles; namely, by passing heated air through textilescontained in a tumbler drum and then discharging to atmosphere. Theentrained water vapor, being a natural ingredient in the air mixture,poses no problem; however, the various cleaning solvents (a commonlyused one is perchlorethylene) are sources of contamination. Furthermore,cleaning solvents are comparatively expensive. It would thus seen thatrecovery of the cleaning solvents would be a common practice; whereas,the reverse is true. This is due to the fact that heretofore solventrecovery systems, tobe efficient, were necessarily large, too large forindividual tumbler dryers, and quite expensive; hence, the presentpractice of wasting the solvent and contaminating the atmosphere.

SUMMARY OF THE INVENTION The present invention is directed to a meansfor controlling the drying of textiles and reclaiming the liquidtherefrom, which may be a solvent other than water or a mixture of suchsolvent and water, and is summarized in the following objects:

First, to provide a means for controlling the drying of textiles whichmay be adapted for use with various types of tumbler dryers to permittheir use for drying textiles containing a cleaning solvent as well aswater or in place of water; the controlling means being particularlyadapted for use in conjunction with the type of tumbler dryer disclosedin my previous U.S. Pat. No. 3,601,903.

Second, to provide a means for controlling the drying of textiles whichfacilitates low temperature drying of the textiles to prevent damage,particularly to synthetic fabrics, and to minimize wrinkling thematerial.

Third, to provide a means for drying textiles containing cleaningsolvent wherein the tumbler dryer need not be sealed to prevent escapeof solvent vapors; instead, the interior of the tumbler dryer ismaintained at a reduced pressure whereby surrounding air flows inwardlythrough any openings that may be present.

Fourth, to provide a drying means as indicated in the preceding objectwherein, by maintaining a negative pressure in the drying drum, thewater or solvent is more readily vaporized at a lower temperature.

Fifth, to provide a means of drying textiles as indicated in the otherobjects, wherein the air and entrained water or solvent vapors are, onissuing from the tumbler dryer, passed through cooling means to condensethe vapors for removal or collection for reuse.

Sixth, to provide a means for drying textiles, as indicated in the otherobjects, wherein a preselected proportion of the air from which theliquids have been removed may be recycled; and wherein the recycled airmay be divided into a heated portion and non-heated portion fortemperature control or, if desired, all the recycled air may be receivedfrom the cooling means thereby to accomplish a cool-out cycle.

Seventh, to provide a means for drying textiles which may be operated asa single pass system; that is, the air may pass'only once through thedrum, then chilled to remove vapors, then discharged; the discharged airhaving minimal contamination, and also being cooled, may be passedthrough activated carbon beds for efficient final cleaning with minimaleffect on the activated carbon bed.

DESCRIPTION OF THE FIGURES FIG. 1 is an essentially diagrammatical frontview of the means for drying textiles showing the path of movement ofthe air.

FIG. 2 is a side view of the tumbler dryer unit at a reduced scale takenfrom 2-2 of FIG. 1 and indicating various typical positions thereof.

FIG. 3 is an enlarged fragmentary sectional view of the inflatable sealmeans taken through 3-3 of FIG. 1.

FIG. 4 is a fragmentary sectional view taken through SPECIFICATION Themeans and method of drying textiles and reclaiming the liquid therefromcomprising the present invention is preferably arranged to utilize thetumbler dryer disclosed in US. Pat. No. 3,601,903 and reference is madethereto concerning the details of construction. The tumbler dryer unitincludes a tumbler housing 1 having a tumbler drum 2 mounted onsupporting and driving rollers 3 or separately driven by means notshown. Each end of the tumbler housing is provided with an access door4, disposed coaxially with the center of rotation of the tumbler drum.

One side of the tumbler housing is provided with a heated air inlet 5and a cooled air inlet 6, which communicate with an arcuate deliveryduct 7 extending over the tumbler drum 2. Below the tumbler drum thereis provided a bellows 8, which forms a discharge duct. As more fullydescribed in the above-mentioned patent, air flows from the deliveryduct 7 into the end portions of the tumbler drum, then travels to thecentral portion thereof for discharge through the bellows 8.

The tumbler housing I is mounted on a base structure 9 and is supportedin such a manner that it may be tilted, as suggested in FIG. 2. The basestructure is provided with a chamber 10 communicating with the bellows 8and provided with a lint screen 11. The chamber 10 communicateslaterally with a first cooling chamber 12 which, in turn, is joined to asecond cooling chamber 13. The second cooling chamber communicates withan outlet 14, situated in the side wall of the base structure 9corresponding to the side wall of the housing having the inlets 5 and 6.

The cooling chambers 12 and 13 are provided, respectively, withcondensing coils I5 and 16, each having a condensate sump 17. The firstcooling chamber and its condensing coil reduces the air temperature to apoint to cause condensation of water vapor from the air but not tofreeze the water. The second cooling chamber and its condensing coiloperates at a somewhat lower temperature than the first coil, but stillabove a freezing temperature, to condense from the air cleaningchemicals present in the textiles.

A common condensate line l8 is connected to both sumps for receivingwater and the cleaning chemical, which is raised by a pump 19 to acollecting and separating vessel 20. The water and cleaning chemical areimmiscible in their liquid phase and have different densities so thatthey may be drawn separately from the vessel 20 to permit reuse,particularly reuse of the cleaning chemical.

The outlet 14 communicates with an air receiving duct 21 which isconnected to a blower 22, having a motor 23. The blower is so arrangedas to produce a negative or subatmospheric pressure at its intake and apositive pressure or ambient pressure at its outlet. As a result, theair in the tumbler drum and the entire ducting within the tumblerhousing 1 is maintained at a sub-atmospheric pressure.

The blower 22 discharges into a stack 24, which discharges the air toatmosphere or into appropriate filters. By reason of the removal of thewater and cleaning liquid, particularly the latter, the discharged airis almost free of contaminants. The residual contaminants are so lowthat complete removal may be attained by use of a conventional activatedcarbon filter at minimal expense.

A heated air entrance duct 25 branches from the discharge stack 24 andcommunicates with the heated air inlet 5. The duct 25 is provided with aheating coil 26. A cooled air entrance duct 27 communicates between thedischarge stack 24 and the cooled air inlet 6. At their junctures withthe discharge stack 24, the ducts 25 and 27 are provided respectivelywith inlet gates 28 and 29, which move into the discharge stack so as todeflect air discharged from the blower 22 into the ducts 25 and 27.

In order to permit tilting of the tumbler housing 1 and also to providea source of ambient air, each duct 25 and 27 is provided with aninflatable seal 30, as shown in FIG. 3. Each seal includes an inletmargin 3] surrounding a corresponding inlet or 6 and a confrontingflange 32 carried by the duct 25 or 27. Each flange 32 carries aninflatable seal tube 33 which, when inflated, engages the correspondingmargin 31. A supply line 34 supplies fluid under pressure to thecorresponding seal tube 33, when it is desired to connect the ducts 25and 27 to the respective inlets 5 and 6. When the seal tubes 33 aredeflated, space is provided between the ducts 25 and 5 and between 27and 6 for the entrance of ambient air into the delivery duct 7.

In addition to the entrances for ambient air provided by the inflatableseals 30, the heated air entrance duct 25 may be providedupstream fromthe heating coil 26 with a pair of ambient air inlet gates 35, as shownin FIG. 4. In order to control the total flow of air, the dischargestack 24 may be provided between the duct 25 and the blower 22 with aflow regulating gate 36.

The flow system provided by the various ducts and the control gates hasseveral modes of operation so that it may be adapted to various cleaningproceduresrln each case, the suction side of the blower draws air intothe tumbler housing so that a negative pressure is maintained in thevarious ducts provided in the tumbler housing. As a consequence, thereis no outward spilling of air to contaminate the surrounding area.Instead, at the various junctures between moving and fixed parts,ambient air is drawn into the system so as to prevent escape of solventvapors in the work area. It is advantageous to draw in ambient air, forthe need for seals is eliminated or at least minimized.

One mode of operation, as indicated in FIG. 5, involves closing theinflatable seals 30, closing the cooled air entrance duct inlet gate 29and opening the inlet gate 28. With this arrangement a selected portionof the air is recirculated past the heating coil 26, and thecomplementary portion of the air is vented through the discharge stack24 so as to regulate the temperature independently of temperatureregulation by adjustment of the heating coil 26.

Another mode of operation is indicated in FIG. 6. Here the inflatableseals 30 are closed, the inlet gate 28 is closed and the inlet 29 isopen, so as to recycle a selected portion of the cooled air dischargedby the blower 22 to effect more efficient use of the air.

A third mode of operation involves the closing of both inlet gates 28and 29, as well as gates 35 and opening the inflatable seals 30. In thiscase, the only air which enters the tumbler drum 2 is ambient air, whichmakes only a single pass through the drum before being vented throughthe discharge stack 24. If it is desired to heat the ambient air, theinlet gates 35 may be open and inflatable seals 30 left open or closedas desired. Again, the air makes a single pass through the tumbler drum.This mode of operation becomes feasible if the ambient air issufficiently low in moisture content and is essentially free ofcontaminants.

By varying the positions of the various gates 28, 29 and 35, and byopening or closing the inflatable seal 30, the mode of operation may beadapted to meet virtually any desired condition and to adjust to variousselected drying times and to adjust to various atmospheric conditions,so that the control system may be readily installed in various existingcommercial laundry or cleaning systems.

In each case, this is accomplished with effective removal of thecleaning solvents for reuse.

While particular embodiments of this invention have been shown anddescribed, it is not intended to limit the same to the details of theconstructions set forth, but instead, the invention embraces suchchanges, modifications and equivalents of the various parts and theirrelationships as come within the purview of the appended claims.

I claim:

1. A dryer means for textiles containing water and a cleaning solventother than water, comprising:

a. a tumbler dryer including a housing structure, a rotatable tumblerdrum mounted in the housing structure, an inlet to the drum and anoutlet from the drum;

b. means defining a flow passage externally of the drum between theoutlet and the inlet;

c. a blower in the flow passage means for recirculating air through thedrum;

d. a heater in the flow passage means;

e. a first condenser unit mounted in the flow passage means downstreamfrom the outlet of the drum, said first condenser unit being temperatureadjusted to condense water vapor issuing from the drum;

f. and a second condenser unit mounted downstream mixture includingwater and a cleaning solvent, comprising:

a. a tumbler dryer including a housing structure and a drum therebybeing restricted communication between the interior of the drum and theexterior of the housing structure for admission of ambient air, an inletto the drum, and an outlet from the drum;

b. means defining a flow passage externally of the drum between theoutlet and the inlet;

c. a blower in the flow passage means for recirculating air through thedrum;

. a heater in the flow passage means;

. a first condenser unit mounted in the flow passage means upstream ofthe blower, said first condenser unit being temperature adjusted tocondense water vapor issuing from the drum;

f. a second condenser unit mounted downstream of the first condenserunit, said second condenser unit being temperature adjusted below thetemperature of the first condenser unit to condense the nonwatercleaning solvent vapor issuing from the first condenser unit;

g. a vent stack communicating with the flow passage means between theblower and the inlet;

h. and valve means for proportioning the air discharged through the ventstack and the air returned to the drum, the returned air supplementingthe ambient air received in the drum to maintain a predeterminedsubatmospheric pressure in the drum thereby to minimize escape ofsolvent vapors from the tumbler dryer.

3. A dryer means for textiles containing a vaporizable cleaning solventmixture, comprising:

a. a tumbler dryer including a housing structure and a drum, and meansproviding restricted communication between the interior of the drum andthe exterior of the housing structure for admission of ambient air, aninlet to the drum, and an outlet from the drum;

b. means defining a flow passage externally of the drum between theoutlet and the inlet;

0. a blower in the flow passage means for recirculating air through thedrum;

d. a heater in the flow passage means between said blower and saidinlet;

e. a condenser means mounted in the flow passage means downstream fromthe outlet of the drum, for condensing cleaning solvent vapors issuingfrom the drum;

f. a vent stack communicating with the flow passage means between theblower and the inlet;

g. a vent stack flow control valve and a heater flow control valve insaid flow passage between said blower and said stack; and

h. an ambient air flow control valve adjacent said inlet;

i. said valves being individually adjustable to proportion the airdischarged through the vent stack and that returned to the drum tomaintain a predetermined subatmospheric pressure in the housingstructure and drum thereby to maintain a flow of ambient air through therestircted communication to minimize escape of cleaning solvent vaporsfrom the drum.

4. A dryer means for textiles as defined in claim 3,

wherein:

a. the said valves valve are operable to close-off backflow to the drumand discharge air from the drum through the vent stack, while ambientair is drawn into the drum.

5. A dryer means for textiles as defined in claim 3 wherein said ambientair flow control valve comprises:

the inlet with respect to the flow passage means.

1. A dryer means for textiles containing water and a cleaning solventother than water, comprising: a. a tumbler dryer including a housingstructure, a rotatable tumbler drum mounted in the housing structure, aninlet to the drum and an outlet from the drum; b. means defining a flowpassage externally of the drum between the outlet and the inlet; c. ablower in the flow passage means for recirculating air through the drum;d. a heater in the flow passage means; e. a first condenser unit mountedin the flow passage means downstream from the outlet of the drum, saidfirst condenser unit being temperature adjusted to condense water vaporissuing from the drum; f. and a second condenser unit mounted downstreamof the first condenser unit, said second condenser unit beingtemperature adjusted below the temperature of the first condenser unitto condense the non-water cleaning solvent vapor issuing from the firstcondenser unit.
 2. A dryer means for textiles containing a vaporizablemixture including water and a cleaning solvent, comprising: a. a tumblerdryer including a housing structure and a drum thereby being restrictedcommunication between the interior of the drum and the exterior of thehousing structure for admission of ambient air, an inlet to the drum,and an outlet from the drum; b. means defining a flow passage externallyof the drum between the outlet and the inlet; c. a blower in the flowpassage means for recirculating air through the drum; d. a heater in theflow passage means; e. a first condenser unit mounted in the flowpassage means upstream of the blower, said first condenser unit beingtemperature adjusted to condense water vapor issuing from the drum; f. asecond condenser unit mounted downstream of the first condenser unit,said second condenser unit being temperature adjusted below thetemperature of the first condenser unit to condense the non-watercleaning solvent vapor issuing from the first condenser unit; g. a ventstack communicating with the flow passage means between the blower andthe inlet; h. and valve means for proportioning the air dischargedthrough the vent stack and the air returned to the drum, the returnedair supplementing the ambient air received in the drum to maintain apredetermined subatmospheric pressure in the drum thereby to minimizeescape of solvent vapors fRom the tumbler dryer.
 3. A dryer means fortextiles containing a vaporizable cleaning solvent mixture, comprising:a. a tumbler dryer including a housing structure and a drum, and meansproviding restricted communication between the interior of the drum andthe exterior of the housing structure for admission of ambient air, aninlet to the drum, and an outlet from the drum; b. means defining a flowpassage externally of the drum between the outlet and the inlet; c. ablower in the flow passage means for recirculating air through the drum;d. a heater in the flow passage means between said blower and saidinlet; e. a condenser means mounted in the flow passage means downstreamfrom the outlet of the drum, for condensing cleaning solvent vaporsissuing from the drum; f. a vent stack communicating with the flowpassage means between the blower and the inlet; g. a vent stack flowcontrol valve and a heater flow control valve in said flow passagebetween said blower and said stack; and h. an ambient air flow controlvalve adjacent said inlet; i. said valves being individually adjustableto proportion the air discharged through the vent stack and thatreturned to the drum to maintain a predetermined subatmospheric pressurein the housing structure and drum thereby to maintain a flow of ambientair through the restircted communication to minimize escape of cleaningsolvent vapors from the drum.
 4. A dryer means for textiles as definedin claim 3, wherein: a. the said valves valve are operable to close-offbackflow to the drum and discharge air from the drum through the ventstack, while ambient air is drawn into the drum.
 5. A dryer means fortextiles as defined in claim 3 wherein said ambient air flow controlvalve comprises: a. an axially extensible and retractible valve devicedisposed between the air inlet and flow passage means for admission,when retracted, of ambient air into the inlet and for sealing, whenextended, the inlet with respect to the flow passage means.